Freezer: do not allow freezing processes to clear TIF_SIGPENDING

Do not allow processes to clear their TIF_SIGPENDING if TIF_FREEZE is set,
so that they will not race with the freezer (like mysqld does, for example).

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Nigel Cunningham <nigel@suspend2.net>
Acked-by: Pavel Machek <pavel@ucw.cz>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/kernel/signal.c b/kernel/signal.c
index 4537bdda1ebfa5c67f1ae8a8aec435c8b01a73b9..909a0cc6bc70a3078f3e41a1e42b94a28cd9ae6e 100644 (file)
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -124,7 +124,7 @@ void recalc_sigpending_and_wake(struct task_struct *t)
 
 void recalc_sigpending(void)
 {
-       if (!recalc_sigpending_tsk(current))
+       if (!recalc_sigpending_tsk(current) && !freezing(current))
                clear_thread_flag(TIF_SIGPENDING);
 
 }